What is the utility of measuring gaseous HgII dry deposition using Aerohead samplers?: A review

• Published in: Science of The Total Environment
• Main Authors: Gustin, Mae Sexauer, Dunham-Cheatham, Sarrah, Osterwalder, Stefan, Magand, Olivier, Dommergue, Aurélien
• Other Authors: University of Nevada Reno, Stanford Synchrotron Radiation Lightsource (SSRL SLAC), SLAC National Accelerator Laboratory (SLAC), Stanford University-Stanford University, Institute of Agricultural Sciences Zürich, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: Cation exchange membranes; Gaseous oxidized mercury; Deposition velocities; Regional trends; [SDE]Environmental Sciences; Indian; Amsterdam Island
• Online Access: https://hal.science/hal-04377431; https://doi.org/10.1016/j.scitotenv.2023.167895

International audience The most efficient way to quantify HgII inputs to ecosystems is to measure wet and dry deposition. Wet deposition of HgII is determined by measuring Hg concentrations and the volume of precipitation. Dry deposition of HgII is determined through direct measurement and/or determined indirectly by measuring air concentrations and using model-generated deposition velocities. Here, data collected using an Aerohead sampler holding cation exchange membranes are summarized, and the utility of this method for understanding dry deposition, and other measurements and processes is discussed. This analysis includes information from publications, and recent data collected at Guadalupe Mountains National Park, Texas, USA, and Amsterdam Island, Southern Indian Ocean. This method primarily measures gaseous HgII and little particulate-bound Hg. The Aerohead method is useful for looking at large-scale trends in deposition, verifying Hg depletion events, calculating dry deposition velocities for compounds with specific chemistry, and identification of sources of HgII. At numerous locations in the western USA, deposition rates were greater at higher elevations due to elevated concentrations associated with longrange transport of atmospheric pollution. When used in tandem with the Reactive Mercury Active System or a dual-channel system, more accurate deposition velocities - that vary as a function of GOM compound chemistry - can be calculated.